This invention relates to volleyball officiating aids and in particular to a volleyball out of bounds detecting and indicating system for improving the quality of judgement calls by officials during play.
The making of out of bounds calls by an official in a fast paced volleyball game is frequently one of judgement and in many instances must be made without assurance that the call is a correct one. In the event that the official is not close to the ball or if there are one or more intervening players screening his view the judgement must be based on where the ball apparently landed. Furthermore, since a ball landing on the line is considered in bounds the call is often critical and even closely observed events can be mis-called.
A review of the prior art reveals that there have been various attempts to solve this problem, especially in related court type sports such as tennis. Generally, apparatus for automatically indicating out of bounds events are either impact sensitive systems or electrical contact type systems. The U.S. Pat. No. 3,415,517 of H.K. Krist entitled Automatic Impact Indication System for Tennis, issued Dec. 10, 1968 and the U.S. Pat. No. 4,092,634 of H. Van Kohorn entitled Electronic Indicator System for Ball Games, issued May 30, 1978 are typical examples.
These systems, however, require making extensive permanent installations in the court and require complex electronic processing equipment. Furthermore, it is often necessary to adulterate the playing balls with either chemicals or electrically conductive elements thus degrading the quality of play.
Electronic eye type sensors have been proposed as a means for detecting out of bounds events. This approach has the advantage of simplicity and does not require permanent court installations. However, there exists the problem of triggering the system by player interruption of the light beam. No currently available system of this type is capable of distinguishing between ball and player.
In view of the foregoing it is seeen that there currently exists the need for court game out of bounds indicating equipment that is simple and inexpensive, that does not require expensive permanent court installation and that is not subject to the ambiguities of currently available electric eye type systems. The present invention is directed toward satisfying that need.